Printed circuit boards with plug-in connectors are, of course, known for a variety of applications. In a typical connector of that type, the plug-in member can be soldered to the printed circuit board and can project therefrom to engage in a socket.
In the case of electric motors wherein the socket may be electrically connected to at least one stator winding, the socket makes electrical contact with the plug-in member which communicates the electrical contact to the solder junctions with the printed circuit board. The socket can form a clamping contact, i.e. a contact which clampingly engages opposite sides of an end of the sheet metal strip forming the plug-in contact. It is important in earlier systems of this type that the sheet metal strip be substantially perpendicular to the surface of the printed circuit board and that it be sufficiently stiff so that, on positioning the printed circuit board in the motor housing, the blade formed by the end of the strip opposite that at which solder joints are formed on the printed circuit, is automatically inserted in the socket or clamping contact with sufficient force to spread the latter and enable a good electric connection to be made.
Because of vibrations inherent in the operation of such motors, the solder junction between the metal strip and the printed circuit board can be subjected to significant mechanical load and can break down, especially with aging of the solder junction and/or as a consequence of the application of elevated temperatures to such junctions. In these cases, the solder joints can be damaged or completely broken. The interruption of electrical connections between the stator winding and the electronic circuitry can result in failure of the electric motor and that, of course, can cause other damage elsewhere in a manufacturing plant or wherever the motor is provided. The maintenance of a reliable electrical connection, in spite of such vibrations, is ensured in the system of DE-OS 196 30 424 in which a higher-current contact plug is connected via an additional flexible conductor, especially via a cable, to a solder junction on the printed circuit board. A drawback of this system is that two separate conductors must be used and must be connected together at the plug-in portion of the contact, thereby raising the number of components required and, more significantly, involving higher mounting costs and requiring increasing amounts of time for creation of the assembly.